Abstract 13624: MADIT II Risk Stratification Scheme Identifies Implantable Cardioverter Defibrillator Patients with High Mortality in a Non-Trial Setting
Introduction: A post-hoc analysis of the MADIT II study showed that patients with a high MADIT II mortality risk score did not benefit from implantable cardioverter defibrillator (ICD) therapy. Whether MADIT II mortality risk score can identify patients who are unlikely to benefit from ICD therapy in a non-trial “real-world” setting is unknown. We hypothesized that ICD patients with a high MADIT II mortality risk score will have a higher mortality and derive less benefit from ICD therapy
Methods: We included 556 consecutive patients who underwent new ICD implantation or generator replacement for primary prevention of sudden cardiac death at the Minneapolis VA Medical Center from 2006 to 2010. MADIT II mortality risk score was calculated for each patient by assigning 1 point each for the presence of age>65 years, diabetes mellitus, NYHA class>II, atrial fibrillation and BUN>28. Patients with score 0, 1-2 and >3 were classified as low, intermediate and high risk, respectively. Follow up was uniform and ICD shocks were adjudicated as “appropriate” or “inappropriate”.
Results: Mean age of the patients was 68±10 years and 99% were male. Of the 556 patients, 10% were classified as low risk, 50% as intermediate risk and 40% as high risk. After 3.3±2.4 years of follow-up, the incidence of appropriate (p=1.00) and inappropriate (p=0.25) ICD shocks was similar in the 3 risk groups (Table). All-cause mortality was higher in patients with a greater risk score (p<0.0001) (Table). However, time from first ICD shock to death (or ICD shock to last follow-up, if the patient was alive), used as a surrogate of survival benefit from ICD, was similar between low, intermediate and high risk patients (p=0.45) (Table).
Conclusions: In a non-trial-based ICD cohort, patients with a high MADIT II risk score have increased mortality but derive similar survival benefit in comparison to patients with lower risk.
- © 2012 by American Heart Association, Inc.